Telegraph transmission system.



LGELL. v TELEGRAPH TRANSMISSION SYSTEM.

APPLICATION FILED MAYZII 1913.

on 1 9 l U 2 e H M u d e t H e t a P 2 SHEETS-SHEET I.

I. GELL.

TELEGRAPH TRANSMISSION SYSTEM.

APPLICATION FILED MAY M. 1913.

Patented June 20, 1916.

2 SHEETS-SHEET 2- vallll $3 47 mm W 4% RECEIVER RECEIVER TRANSMITTERPERFORATOR TRANSMITTER PERFORATOR JOHN GELL, OF LONDON, ENGLANDTELEGRAPH TRANSMISSION SYSTEM.

To all whom it may concern Be it known that I, JOHN GELL, electricalengineer, residing at London, England, have invented certain new anduseful Improvements in Telegraph Transmission Systems; and I do herebydeclare the following to be a full, clear, and exact description oftheinvention, such as will enable others skilled in the art to which itappertains to make and use the same.

The invention consists of apparatus for the purpose of bringing intoaction certain instruments in proper sequence, in order that the speedof transmission may be relatively high, while the individual speed ofthe sending or receiving operator may be low.

In order to clearly indicate the action of the apparatus, and the systememployed, reference is made to the accompanying drawings in which Figure1 is a plan of a 2 unit switch, Fig. 2 is a Vertical section of thesame, Fig. 3 is a plan of one of the switching elements in a 4 unitinstrument, Fig. 4 is a section of Fig. 3, Fig. 5 is a plan of a 2 and 3unit instrument with the 4 switching drums on the same shaft, Fig. 6 isa diagram of the electrical connections at the sending station, Fig. 7is a diagram of the electrical connections at the receiving station.

In the difierent figures, the same number or letter represents the samepart.

In Fig. 1, A is the connecting block to the A transmitter on the lineside, and A the connecting block to the A transmitter on the motor side.In like manner B and B are the connecting blocks to the B transmitter onthe line and motor side respectively, L is the connecting block to themain line and M is the connecting block to the source of electricalenergy. 1 is the connecting spring between A and one of thetoothedconducting rings 9 of the switching drum on wheel 7; 10 is a similartoothed conducting ring on 7, meshingbut not in contact with 9, 3 is thespring which connects 10 to B; 2 is the spring which connects the lineblock L alternately to 9 and 10 respectively as the drum is rotatedtooth by tooth in the well known manner of a sunflower wheel.

In like manner, springs, 4, 5, and 6 connect A and B to toothedconnecting rings 11 and 12 not shown. 7 is the complete sunflower wheelwhose step by step movements connect the main line alternately to theline terminals of the A and B transmitters. 8 is Patented June 26,1916.. Serial No. 769,023.

a similar wheel to 7, but shown in section to indicate how the ebonitemain wheel is' connected to the main shaft 13. It is similar to 7, andcarries out the, same function with respect to the motors of the A and Btransmitters as 7 does to the line circuit; 14 and 15 are the bearingsof the main shaft. 16 is a toothed lever pivoted at 17 on bearing 18 andengages with ratchet wheel 19 on the completion of its upward movement;the end of 16 remote from pivot 17 is pivoted to connecting rods 20. 21is a ratchet wheel similar to 19, but with its teeth facing in thereverse direction to 19. Both 19 and 21 are firmly fixed to the mainshaft by means of collar 22; 23 are a pair of radial arms pivoted on 22and carrying a pawl 22 which engages in wheel 21. The opposite ends of23 are pivoted to connecting rod 24; connecting rod 24 at the oppositeand lower end is pivoted by means of a connecting piece to the yokepiece 25 of the cores 26 and 26 of the solenoids 27 and 27 and '28 and28 are the insulated connecting screws to the solenoids 27 and 27 29 isa block of glgolllgite carrying the blocks A, L, B and A In Fig. 2, 30is the main yoke piece of solenoids 27 and 27 connecting the bases ofsolenoids 27 and 27 and also by means of screws 31, holding them againstthe main plate 32; 33 is a stop to regulate the lower movement of thesolenoid cores 26 and 26.

In Fig. 3, 34, 35, 36, 37, 38 are connecting springs with functionssimilar to 1, 2 and 3; 39 are studs which engage with 36 the lineterminal spring; 40 is a stud which engages through 34 with transmitterA, in like manner 41 engages with transmitter B; 42 with transmitter Othrough 35; and 43 with transmitter D through 37. 40, 41, 42 and 43 areconnected by pins or screws as shown by dotted lines to the studs 39 ina line with them.

In Fig. 4, the studs 39 are shown recessed into the ebonite, slightlyprojecting above,

its surfaceand with the ends of the connecting pins indicated.

In Fig. 5, on the same shaft, are shown a pair of wheels 43 and 44 whichperform the same function as 7 and 8-Fig. 1;' 45 and 46 are similar to43 and 44, but each has an additional connecting spring and series ofstuds to form a triple wheel for transmitters A, B and C; 47 arerecessed rings to carry out the same function as the ,stone transmitter;64 is the B transmitter; 65 is a perforator for preparing the well knownWheatstone transmitting tape. It is actuated'by electricity; controlledby keys similar to that of'a typewriter. It is used in connection withthe. A transmitter; as the operator prepares the tape, it passescontinuously into the transmitter 63, the punches of the perforator andthe feed wheel of the transmitter being in line; 66 is the perforatorused in connection with the B transmitter in the same manner as that ofthe transmitter A and 65.

In Fig. 7 is shown the-switch in use at the receiving end of the line;67 is a sluggish relay, 68 is a suitable receiving instrument such as aWheatstone motor driven tape recording receiver on the A side; 69 is asimilar receiver on the B side; 1, 2, 3,

'4, 5, 6 are the springs in connection with the sunflower wheel'asindicated in Fig. 1, and 27 and 27 are the solenoid coils actuating theswitch.

Having therefore described the purport of the different figures, bytheir aid I shall now-describe the action of the switch, and

in'the first place refer only to two circuits.

The messagesto be transmitted are placed before the operators workingthe perforators 65 and 66Fig. 6, and let us assume that' th'e operatorswill maintain an average speed of 50 words per minute. Transmitters 63and 64 are speeded up to 100 words per minute. The operators bothstartperforating the messages before then, and when they have eachalmost completed the first one, both the transmitters are switched on inthe usual manner, but only.one transmitter will start running accordingto the position of the sunflower wheels. Let us assume that the linecontact spring 2 is connected through 9 to 1Fig. 1, then transmitter Ais in a positionto send signals to line. At the same time, contactspring 5 will be connected to. 4 through 11 Fig. 1, and the motor of Atransmitter will be "actuated by the main driving current.-

Each operator has placed the end 'of the tape under the feed wheels oftheir respective transmitters, but only the A transmitter startsrunning, and sends out to line the signals which are controlled by thetape from the A perforator. The operators hav- .be able to feed it.

ing finished their messages will each depress the special key whichrecords on the tape one marking hole.

The message slgnals going out to line from the A transmitter do notaffect the relay 62 which is biased to the spacing side, because theyare alternating and of short dudoing so they actuate the radial arm 23,

through levers 24 and 25. The radial arm by means of its pawl acting onratchet wheel 21 moves the whole mechanism on shaft 13-Fig. 1, thedistance of one tooth. Lever 16 connected to the radial arm 23 throughthe connecting rods 20 moves upward until its tooth engages in the checkratchet wheel 19 and so provides a positive stop to the motion andprevents overfeeding by the momentum set up.

As soon as the sunflower wheels have moved forward one segment asdescribed, for the teeth of the feed wheel are working in harmony withthe conducting segments, thenthe current ceases to flow through motor 63on the A side, but starts the motor in 64 on the B side; at the sametime the transmitter 63 on the A side is cut out of the line circuit,and transmitter 64 on the B side is switched in. The message thereforethat has been perforated by the B perforator on 66 is now going out toline; as soon as the special marking hole on the B tape reaches thetransmitting pins a long current goes to line, the B transmitter isstopped, and the A transmitter started, and so each transmitter in turnis brought in and out of operation.

Should one .of the telegrams be specially long, for instance on the Aside, then the operator at the B perforator will refrain. from pressingthe special key until he has perforated two or more messages. In likemanner, if one operator is faster than the other, then the fasteroperator will occaby omitting to depress the special key at the end ofthemessage. Therefore, so long as the total speed of the operators isequal to the speed of each transmitter, there will be no need to reducethe working speed.

In the event of a circuit carrying 150 words per minute, two operatorswould not It would then be necessary to use a three unit wheel, similarto 45 and 46, (Fig. 5) and three perforators and transmitters instead oftwo. In like manner, if it became necessary to send 200 or more wordsper minute, 4 or 5 unit wheels would be required.

memes Figs. 3 and 4 show a special construction v of a 4 unit wheel, and45 (see Fig. 5) a modification of the same type of wheel.

As the traflic varies during the day, it is quite possible that on athree unit circuit, there might at one time be only suflicient trafficfor one operator to cope with; at another time two would be suiiicient;and at another time the three would be required. It is thereforeessential that the apparatus shall be so arranged as to meet the difi'erent conditions. Vhen the traflic is at its minimum the relay 62 isshort circuited, and only one transmitter is used. When the workincreases the two unit wheels are brought into circuit 43 and 44, Fig.5, in the well known manner, either apart from or incorporated in theautomatic switch, of a double two way switch controlling the line andmotor Circuits of wheels 43, 44, 45 and 46. Contact spring 53 would beconnected to line and also 56 to the main motor driving circuit. Vhenthe work increases the three unit wheel would be brought into circuit bycrossing the switch over to 50 and 60.

There is a second means of obtaining a variation in the number of unitsin use. Take for example, the 4 unit wheelFigs. 3 and 4, with 4transmitters connected up. Upon each of these transmitters there is aspecial switch so arranged that when it is in the on position, a markingcurrent is sent to line whenever the-segment of the sunflower wheelcontrolling that transmitter is connected to line. Let us assume thatthis circuit with 4 units is required to work as a 2 unit. Ihentransmitters l3 and D will have this special switch to the on andtransmitters A and C will have their special switches to the oil, and beacting as previously described.

In the event of only one sending unit and two receiving units being incircuit, it is necessary that the single marking hole be.

supplen'iented on the sending tape by a spacing hole at an interval ofat least 10 holes, or the marking current will continue onto the firstmessage signal and mutilate the first signal succeeding it.

In place of the Vheatstone apparatus as described, other telegraphinstruments may be used. For instance, reperforators may replace thereceivers and in turn actuate other separate apparatus.

I claim 1. A system of the class described com- 'and means whereby saidtransmitters may be successively started or arrested, substantially asdescribed.

3. A system of the class described com prising a plurality oftransmitters, means for alternately actuating said transmitters .andmeans whereby said transmitters may be successively started or arrestedby an actuating or arresting signal sent to line, substantially asdescribed.

4. A system of the class described comprising a plurality oftransmitters, a switch for putting said transmitters individually in andout of line and means for sending a-special marking signal to line toactuate said switch to put another transmitter into circuit with line,substantially as described.

5. A system of the class described comprising a plurality oftransmitters and means actuated by a perforated signal for putting saidtransmitters in and out of the line circuit, substantially as described.

6. A system of the class described comprising a plurality oftransmitters, including means for making a prolonged signal, and meansfor transmitting said signal to line, a relay in circuit with the line,and a throwover switch adapted to be operatedby said relay whereby thecurrent is open to one transmitter and closed to another.

7. A system of the class described comprising a plurality oftransmitters, means for operating said transmitters, a relay in linecircuit having a local source of energy adapted to complete or break thecircuit to said operating means.

8. In combination in a system of the class described, a plurality ofindividually operated transmitters, sunflower wheels for putting saidtransmitters in and out of line circuit, and actuating means for saidwheels, operated by a perforator signal.

In testimony whereof I affix my signature, in presence of two witnesses.

JOHN GELL.

